In a case where a plurality of users simultaneously edit program components with respect to a certain programmable logic controller in a programmable logic controller system, by adding lock information indicating possibility of making edition for each of the program components stored in the programmable logic controller, the possibility of edition for each of the program components can be monitored, and the users can simultaneously edit data. (Refer to Patent Literature 1.)
Also, in a case where a plurality of users are concurrently connected to a certain target device, when a certain client device registers shared data, the registered content can be immediately reflected to client devices other than the client device that has registered the data therein. (Refer to Patent Literature 2.)